A Case Report of a Rare, but Important, Cause of Delerium Presenting to an Emergency Department

INTRODUCTION: Delayed post-hypoxic leukencephalopathy is a rare cause of acute neuropsychiatric decline diagnosable in the emergency department (ED), but it has not been described in the emergency medical literature. We present a case report of a pathognomonic presentation. CASE REPORT: A 53-year-old man developed akinetic mutism 14 days after being discharged from a hospitalization for fentanyl overdose. Magnetic resonance imaging demonstrated symmetric frontoparietal white matter demyelination. CONCLUSION: Delayed post-hypoxic leukencephalopathy can present to the ED as altered mental status days to weeks after apparent full recovery from an initial episode of cerebral hypoxia. This report will help emergency physicians avoid missing this diagnosis.